Gasoline compositions

ABSTRACT

A method of reducing intake valve deposits formed in a spark ignition gasoline-fueled internal combustion engine is disclosed. The method features the use of gasoline containing a deposit reducing amount of a high molecular weight alkyl aromatic hydrocarbon or mixture of alkyl aromatic hydrocarbons. The gasoline compositions and gasoline additive concentrates are also disclosed.

limited States Patent 1191 Perilstein 1451 Sept. 11, 1973 1 GASOLINE COMPOSITIONS [75] Inventor: Warren L. Perilstein, Orchard Lake,

Mich.

[73] Assignee: Ethyl Corporation, Richmond, Va.

[22] Filed: May 26, 1971 [211 App]. No.: 147,235

Related US. Application Data [62] Division of Ser. ,No. 828,753, May 28, 1969,

abandoned.

[52] US. Cl. 260/668 R, 260/671 B, 260/671 G [51] Int. Cl C07c 15/04, C07c 3/56 [58] Field of Search 260/671 B, 671 G,

[56] References Cited UNITED STATES PATENTS 3,109,869 11/1963 Chambers et a1. 260/671 B Pappas et al. 260/671 B Culbertson et al. 260/67! G Primary Examiner Curtis R. Davis AttorneyDonald L. Johnson, Robert A. Linn and Daniel T. Szura [5 7 ABSTRACT 2 Claims, No Drawings GASOLINE COMPOSITIONS CROSS REFERENCE TO RELATED APPLICATION This application is a Division of Ser. No. 828,753, filed May 28, 1969 now abandoned.

BACKGROUND OF THE INVENTION During the operation of a spark ignition internal combustion engine, deposits are formed on portions of the intake system. The intake system is that part of the engine before the combustion chamber (cylinder) containing an intake valve deposit reducing amount of through which the airfuel mixture is conducted. These deposits are apparently residues formed when the fuel and/or lubricant oil used inthe engine contact the hot surfaces within the intake system. The deposits which form on the intake valve stem and the side opposite the valve face (underhead) are of special concern. Such deposits contribute to the intake valve failure by causing the valves to overheat for example; these deposits may also prevent proper seating of the intake valves which would result in engine malfunction. Thus, it is desirable that the formation of these deposits be minimized. f

Additives to prevent or reduce engine deposits are disclosed in the art; see US. Pat. No. 1,692,784, US. Pat. No. 2,066,234, US. Pat. No. 2,080,681, U.S.Pat. No. 2,103,927, and US. Pat. No. 2,726,942. One disadvantage of knownadditives is that relatively high concentrations are required'for good effectiveness.

It has been discovered that a relatively small amount of a high molecular weight alkyl aromatic hydrocarbon such as an alkyl benzene or mixture of alkyl benzenes, is extremely effective as an additive. in gasoline for preventing undesirable intake system deposits; and especially the aforesaid intake valve deposits.

SUMMARY OF THE INVENTION A method of reducing deposits formed on the intake valves of a spark ignition internal combustion engine by burning in said enginegasoline containingfrom about 50 to about 1,000 parts per million by weight of an alkyl aromatic hydrocarbon or mixture of alkyl aromatic hydrocarbons having (a) at leastonealkyl group of at least 12 carbon atoms and (b) an average molecular weight of at least about 400; the gasoline composition containing said alkyl aromatic hydrocarbons'or the aforesaid alkyl aromatic benzenes. A useful concentration of this additive in the gasoline is from about 50 to about 1,000 parts per million by weight; gasoline containing 100 to 800 parts per million of the alkyl aromatic hydrocarbon is preferred. A more preferred gasoline composition also contains a suitable metalloorganic antiknock agent and a halohyd rocarbon scavenger.

In preparing the gasoline fuels of the present invention'the alkyl aromatic hydrocarbon additive can be added directly to the gasoline; or the additive can be made up as a concentrate in a suitable inert diluent, if

' desired, and then added to the gasoline. This additive concentrate can, also contain other gasoline additives such as metallo-organic antiknock agents, halohydrocarbon scavengers, dyes, surface ignition suppressors such as organic phosphates, carburetor detergents, an-

- alkyl group having 12 or more carbon atoms. The avermixtures thereof; and gasoline additive concentrates useful'for' preparing said gasoline compositions.

DESCRIPTION or THE PREFERRED EMBODIMENTS a The present invention is directedto a method of improving spark ignition, internal combustion engine operation by reducing deposits formed in the intake system and especially onv the underhead intake valve, by

burning in said engine gasoline containing from about.

50 to about 1,000 parts per million (ppm) by weightof an additive which comprises alkyl aromatic hydrocarbons having (a) at least one C or longer alkyl group and (b) a molecular weight'of at least about 400. Alkyl benzenes and mixtures'of aklyl benzenes are preferred.

age molecular weights of usefulalkyl aromatic hydrocarbons will generally range from about 400 to about 1,200 or more. The aikyl groups maybe linear or branched. Alkyl aromatic hydrocarbons include monoas well as polyalkyl compounds; thearomatic portion of the alkyl aromatic hydrocarbon includes benzenes such as benzene, toluene, diphenyl and the like as well as polynuclear (fused ring) benzenes such as the naphthalenes, fluorene, phenanthrene andtheilike.

. Examples of useful monoand polyalkyl polyriuclear .benzenes are l-n-dodecylphenanthrene l-n-octadecylnaphthalene 1 2-n heneicosylanthracen'e 2-eic'osyll -methylanthrac ene nedoc osylphenanthrene Z-tetracoSylnaphthalene l-( l-octyl-n-de,cyl)naphthalene l-eicosylfluorene 7-pentacosylindene l,2-didodccylanthracene I l ,2,9-tripentadecylanthracene l-decyl-2-tetracecylanthracene 1, l O-dieicosylphenanthrene 1,4-dipentadecyl-2- methylanthracene 4-heptacosenyll -methylan thracene l,4-di( 2-butyl-n-octyl)phenanthrene l,Z-ditridecylnaphthalene 1,3-diheneicosyl-Z-methylnaphthalene l-octyl-2,5,6-tridodecylnaphthalene 1,2,4-tritetradecylnaphthalene l-propyl-2-tricontylnaphthalene 1,4-didocosylnaphthalene 4,7-di(2-hexyl-n-decyl)indene 1,2-dinonadecylfluorene 1 ,4,7,8-tetra( l ,3,5,7-tetramethyl-n-octyl)fluorene and the like.

Alkyl benzenes and polyalkylbenzenes are preferred alkyl aromatic hydrocarbons. Examples of such preferred hydrocarbons are:

n-triacontylbenzene hexacosyldiphenyl 1-(2-hexyl-n-dodecyl)diphenyl 1,1 -di( 1 ,3,5,7,9-pentamethyl-n-decyl)diphenyl 3-tetracosyldiphenyl n-docosylbenzene dotriacontylbenzene 1,6-di(2-buty1-n-decyl)benzene 1,2-didodecylbenzene 1-decyl-2,4-didodecylbenzene 1,2,4-trioctadecylbenzene 2-decyl-4-dodecyltoluene 2-hexacosyl-p-xylene 4-octacosyltoluene l-docosyldiphenyl 3,3-diheptadecy1diphenyl l-methyl-l -heneicosyldiphenyl 1,1 ',2-nonadecyldiphenyl 2,4,6-tridodecyl-1,3 ,5 -trimethylbenzene 1,4-di( 2-hexyl-n-octyl)benzcne 6-eicosyll ,3-dimethylbenzene 2 ,4-didocosyl-1-tert-butylbenzene 1,1 ,3,3'-tetradocosyldiphenyl 4-dotriacontyl- 1 ,Z-dimethylbenzene 1-methyl-2,4,6-tri(1,3,5,7-tetramethyl-n-octyl) benzene 1,3 ,S-triheneicosylbenzene 1-isopropyl-2,6-dioctadecylbenzene 1-octyl-4-heptacsylbenzene l-pentyl-2,-dihexadecylbenzene l,4-dimethyl-2,6-ditridecylbenzene 2-dotriacosyl-l-methylbenzene and the like.

Another preferred alkyl aromatic hydrocarbon is the product obtained on alkylating an aromatic hydrocarbon with a suitable olefin or mixture of olefins. Any effective method for alkylating aromatic hydrocarbons can in general, be used. A convenient alkylation process is that commonly known as the Friedel-Crafts process. Basically, the Friedel-Crafts process involves the treatment of an aromatic hydrocarbon with an olefin or mixture of olefins inthe presence of a strong Lewis acid catalyst such as the aluminum halides, BF HF, H 80 P FeCl,, SnCl ZnCI and the like. Aluminum chloride and aluminum bromide are preferred catalysts. Generally, aromatic alkylation procedures such as the Friedel-Crafts process produce a mixture of monoas well as polyalkylated aromatic hydrocarbons. Although it can be separated into its components the mixture without any separation is quite useful in the present invention. Examples of Friedel-Crafts alkylation procedures and products will be presented below.

The aromatic hydrocarbons which can be alkylated to produce additives of the present invention include the benzenes such as benzene, diphenyl, lower alkyl benzenes such as toluene, xylene, isopropylbenzene, C,-C, alkyl benzenes, C,-C alkyl diphenyls, and the like; as well as polynuclear (fused ring) benzenes such as naphthalene, methylnapthalene, phenanthrene, in-

dene, fluorene and the like. The benzenes are preferred aromatic hydrocarbons; benzene is a most preferred aromatic hydrocarbon.

Olefins having 12 or more carbon atoms are useful for alkylation. The olefins may be branched or linear, aor internal olefins.

Examples of useful olefms are:

l-dodecene, l-hexadecene, 2-eicosene, triisobutylene, propylene tetramer, 3-pentadecene, l-tricontene, 2-dotriacontene, 2-tetracosene, 3-octacosene, 2- nonadecene, 4-heneicosene, 1,2-diethyl-1-decene, 3- ethyl-3-dodecene, 2-octyl-1-hexadecene, mixtures thereof and the like. Mono-olefins are preferred.

Mixtures of commercial olefins are preferred for the alkylation. These commercial olefins are mixtures obtained from processes such as Ziegler catalyzed ethylene and/or propylene polymerization; catalytic dehydrogenation of suitable paraffins, e.g. wax cracked paraffins, and other similar processes. These commercial olefin mixtures can vary widely in composition from l0 a-mono olefins, through intermediate mixtures, to 100/0 internal mono olefms. The range of carbon chain lengths in these mixtures can also vary considerably. Both branched and linear olefins can be present in these mixtures. Useful mixtures can also contain up to 10l0 by weight of C -C olefins. Mixtures in which a-monoolefins predominate are preferred; by predominate is meant that more than 50l0 by weight of the olefin mixture is amonoolefin.

Examples of useful preferred commercial mixtures are those having the following olefin compositions by weight: 30l0 C 40/0 C and 30/0 C, ;l0/0 C 20/0 C 25/0 C 25/0 C l5/0 C and 5/0 C 2/0 C 3/O C 5/0 C 30/0 C 35/0 C 20/0 C and 5l0 C 1/O C 1/0 C 2/0 C 15/0 C 2I/0 C 24/0.C 20l0 C 10/0 C 4/0 C and 2/0 C 50/0 C and 50/0 C 20/0 C 60/0 C and 20/0 C 5/0 C l5/0 C 30l0 C 32/0 C l0/0 C and 8l0 C 15/0 C 18l0 C 30/0 C 20l0 C and 7/0 C 2/0 C 5/0 C 10l0 C 12/0 C 18/0 C 30l0 C 15/0 C 5 and 8/0 C and the like.

A more preferred commercial mixture of olefins is one containing even carbon numbered olefins, ranging from about C to about C the olefins are predominately a-mono-olefins'. These mixtures can also contain smallamounts of C C and C olefins as well as C and higher olefins; These more preferred olefins will be designated herein as c qolefins or C mixtures. Ex-

amples of typical C olefins are listed in the following table.

TABLE 1 C Olefin Mixtures Percent'By Weight Olefin Carbon No. A- B C D C C 1,84 1.40 2.01 C" 20.39 16.72 19.40 0.3 C 12.15 9.76 12.59 26.5 C 10.65 8.28 10.97 58.0 C 6.29 6.34 8.88 12.9 C, 4,35 4.43 5.15 C 3.25 5.59 6.63 C 4.38 7.50 7.70 C 3.51 6.41 4.78 C 2.07 3.69 2.40 C 1.33 1.25 0.90 C 0.38 0.17 C 0.08 Total Olefins 70.21 72 81.58 97.7 Total Paraffins 18.30 28 18.42

Other By-Products l L49 2.3

Olefin Configuration Percent Distribution :1 69.7 60.6 Internal 30.3 39.3 Vapor phase chromatographic analysis Estimated Nuclear magnetic resonance analysis Most preferred commercial olefin mixtures are mixtures of predominantly a-monoolefins of even carbon number ranging from C, C Again, small amounts of olefins outside this range can also be present. These most preferred olefin mixtures will be referred to herein as C olefins or C olefin mixtures.'A general composition range of these C olefins is set out in the following table:

TABLE 2 C Olefin Composition Range Olefin Percent Carbon No. Percent By Weight C 0-6 C 0.5-22 C 32-55 C,, 18-39 C I 6-16 C 0.5-8 C 0-10 Paraffins 0-10 Olefin Configuration Percent Distribution 0: (Vinyl 30-55 (Vinylidene 30-50 internal -32 Vapor phase chromatographic analysis C includes C and lower olefins C includes C and higher olefins Nuclear magnetic resonance analysis Specific examples of C and olefin compositions are given in the following table.

lntvrnul 15.4 13.8 12.0 15.6 20.4 30.4

1 Vapor plmsn chromatographic analysis. 2 Nuclear nmguutic resonance analysis.

As pointed out above, the additives useful in the present invention are preparedby alkylating aromatic hydrocarbons. The following examples illustrate alkylution processes which produce alkyl aromatic hydrocarbon products useful in the present invention. All parts are by weight unless otherwise specified. All molecular weights were determined by vapor phase osmometry. The C olefins utilized in these examples fall within the general composition set out in Table 2.

EXAMPLE 1 A solution of 120 parts of benzene and 600 parts of a C olefin mixture was placed into a suitable vessel, fitted with a stirrer; to this solution was added portionwise over a 20-minute period 30 parts of an anhydrous aluminum chloride. During this addition of aluminum chloride the temperature ranged between 30 and C. (the solution was stirred during the addition). The reaction mixture was heated to C. and stirred for two hours at this temperature. Then, about l50 parts of a l0/0 HCl solution was added. About 100 parts of benzene were added to reduce the viscosity of the mixture; the reaction mixture was then washed with water until the washings were no longer acid to litmus. The washed product was stripped under vacuum on a steam bath. The product obtained was 605.4 parts of a yellow, slightly hazy liquid. The molecular weight of the product was 799. The infrared spectrum of the product indicated that it contained a substantial portion of alkylated benzenes.

EXAMPLE 2 Following the basic procedure of Example 1, 60 parts of benzene was'reacted with 300 parts of the C olefin mixture, using 15 parts'of AlCl catalyst for 5 hours at 70C. The-yield of product was 297 parts; the molecu larweight was 792.

EXAMPLE 3 Following the basic procedure of Example 1,-240 parts of benzene were reacted with l250 parts of the C olefin mixture using 50 parts of AlCl -catalyst at 70C. for 2 hours. Total product yield was 1250 parts; the molecular weight was 772.

Similar results are obtained carrying out the process of Example 1 when aluminum bromide is used in place of the aluminum chloride.

EXAMPLE 4 A solution of 1400 parts of C olefin mixture and 270 parts benzene were charged into a suitable vessel equipped with a stirrer. To this solution was added 16 parts of aluminum chloride in small portions over a 2-4 minute period (the solution was stirred during the addition). Themixture was then heated to C. for 2% hours with stirring; then about 200 parts of a l0l0 l-ICl solutionwas added. Benzene was added toreduce the viscosity and the solution was washed with 200 part portions of water until the washings were free of acid (litmus paper). The washed benzene solution was filtered through Celite and then stripped under vacuum. The yield was946 parts of a clear yellow liquid having a molecular weight of 703.

EXAMPLE 5 mixture, 264 parts .ofbenzene and 66- parts of aluminum chloride. This reactionyielded 1128 parts of a liquid producthaving a molecular weight of 774.

Similar results are obtained when diphenyl, toluene or tert-butyl benzene are used in place of the benzene in Examples l-5. Aluminum bromide or BF is also used successfully as a catalyst in place of AlCl C, olefin mixture E, G, and H also yield a' satisfactory product in the processes of Examples 1-5.

EXAMPLE 6 The following three alkylations were run using basically the same procedure as in Example 4. Run A l ,500 parts of a C, olefin mixture was reacted with 300 parts of benzene using 75 parts of AlCl catalyst at a temperature of 70C. for 2 hours. The product obtained was a clear yellow, oily liquid; the yield was 1411 parts; the molecular weight was 787. Infrared analysis showed the presence of a mixture of alkyl benzenes. Run B 1,500 parts of a C olefin mixture was reacted with 300 parts of benzene using 75 parts of MCI, catalyst at a temperature of 7074C. for 2 hours. The product obtained was a clear yellow, oily liquid; the yield was 1,389 parts; the molecular weight was 775. Infrared analysis showed the presence of a mixture of alkyl benzenes. Run C 1,500 parts of a C olefin mixture was reacted with 304 parts of benzene using 76 parts of AlCl catalyst at a temperature of 70C. for 2 hours. The product obtained was a clear yellow, oily liquid; the yield was 1,488 parts; the molecular weight was 764. Infrared analysis showed the presence of a mixture of alkyl benzenes.

The products from Example 6, Runs A C were blended. The resulting blend has a molecular weight of about 775.

EXAMPLE 7 A catalyst complex was prepared by adding 48 parts of tert-butyl chloride in 65 parts of benzene to 20 parts of anhydrous AlCl in a suitable vessel while anhydrous HCl was slowly swept through. To this was added dropwise, with vigorous stirring, a solution of 92.2 parts of naphthalene, 100.8 parts of C olef n mixture and 150 parts of benzene. The addition required 30 minutes; the reaction mixture was stirred for an additional 30 minutes at 3040C. The black reaction mixture was washed first with about 250 parts of 5/0 I-lCl, then four times with 125 parts-of water; and then the reaction mixture was stripped under vacuum on a steam bath. Infrared analysis of the product at this point showed that some unreacted naphthalene remained. The product was then extracted six times with about 25 part portions of dimethylsulfoxide and then'washed with water. The washed product was stripped under vacuum on a steam bath. The product yield was 114.2 parts of a dark, mobile liquid. The molecular weight of this product determined by vapor phase osmometry was 398. Infrared analysis of the product showed the presence of alkylated naphthalenes and substantially no unreacted naphthalene.

The basic procedure of Example 7 is described in US. Pat. No. 2,541,882.

EXAMPLE 8 The procedure of Example 4 was used except that the amount of olefin was doubled (200 parts). Additionally after extraction-with dimethylsulfoxide and water, the product was dried over Na SO and then it was finally stripped. The yield was 223 parts of a clear, brown, fairly mobile liquid; the molecular weight, by vapor phase osmometry, was 432. Infrared analysis of the product showed the presence of alkylated naphthalene and the absence of unreacted naphthalene.

When substantially the same reaction as in Example 7 was run at 100C. for 2 hours, without any benzene present during the reaction period, the product yield was 196.7 parts; the molecular weight of this product was 557. The product was substantially free of unreacted naphthalene. Infrared analysis showed the presence of alkylated naphthalenes.

EXAMPLE 9 A mixture of 461 parts of naphthalene and 1225 parts of a C, olefin mixture was placed into a suitable vessel; the mixture was heated until it became homogeneous. Anhydrous AlCl (81 parts) was added gradually to the reaction mixture at a rate that maintained the temperature at C. for 6 hours. Then, about 300 parts of a 5/0 I-ICl solution was added. The product mixture was diluted with 150 parts of benzene and washed with 250 parts portions of water until the washings were no longer acid to litmus. The solvent was stripped under vacuum and the unreacted naphthalene was removed by distillation at temperatures up to 200C. and under 10 mm. pressure. The yield of liquid product was 1,436 parts; the molecular weight was 647.

Similar results are obtained when phenanthrene, fluorene, indene, or methylnaphthalene are used in place of the naphthalene. Catalysts which are also effective are BF SnC1 and HF. The C olefin mixtures A and B, wax cracked olefin mixtures, heptadecene, and propylenetetramer also yield good results when used in place of the C olefins.

Useful alkylated aromatic hydrocarbons having an average molecular weight between 400 and about 1,200-are also obtained from the reaction of (a) ndodecene and toluene, using aluminum bromide catalyst, (b) a mixture of 20/0 C 40/0 C 20/0 C l0/0 C l0/0 C olefins and xylene using BF catalyst, (c) C Olefin Mixture A (see Table l) and Z-methylanthracene using H catalyst, (d) a mixture of C C C olefins and fluorene using HF catalyst, (e) C Olefin Mixture B (Table 1) and phenanthrene using P 0 catalyst, and (f) wax cracked olefins and diphenyl using ZnCl catalyst. f

In carrying outthe Friedel-Crafts alkylation illustrated by the previous examples, the reactant ratio can be varied. Molar ratios of olefinzaromatic hydrocarbon can range from about 1:1 to about 10:1; molar ratios of 2:1 to 10:1 are preferred. I

Any suitable Friedel-Crafts catalyst can be used; alu-' minum chloride and aluminum bromide are preferred. Any suitable amount of the catalyst can be used. Molar ratios of the aromatic hydrocarbonzcatalyst can range from 1:1 to about 10:1; preferred aromatic hydrocarbon:catalyst ratios are from about 4:1 to about 10:1.

The Friedel-Crafts alkylation can be carried out at any suitable temperature. Ordinarly, the reaction is carried out at atmospheric pressure. When carried out at atmospheric pressure, the limiting reaction temperature is the boiling point of the lowest boiling reactant. This, for atmospheric pressure alkylations, temperatures can vary from as low as 30C. up to the boiling point of lowest boiling reactant. If the reaction is carried out under pressures about atmospheric, the upper temperature limit is consequently raised.

The FriedeLCrafts alkylation reaction time is dependent to a certain extent on other parameters such as for example temperature, activity of the reactants, type of catalyst. Thus, the reaction time can be varied over a wide range. Reaction temperatures of from 15 minutes up to 24 hours can be used.

The Friedel-Crafts alkylation can be carried out, if desired, in the presence of a solvent which is inert'for the purposes of the desired alkylation. Examples 7 and 8 illustrate such a solvent use. Other similar solvent systems can be used.

As pointed out above, any procedure for alkylating aromatic hydrocarbons, which produces alkyl aromatic hydrocarbons as characterized above, can be used. Thus, for example, Friedel-Crafts alkylation, utilizing, as alkylating agents, alkyl halides or alkanols corre-- sponding in type to the olefins described above, can be used to make additives of the present invention.

In preparing gasoline compositions suitable for use in the present invention, any internal combustion engine gasoline base fuels may be used. Gasoline is generally a blend of hydrocarbons boiling from about 25C. to about 225C. which occur naturally in petroleum and suitable hydrocarbons made by thermal or catalytic cracking or reforming of petroleum Hydrocarbon compositions of typical base gasolines are tabulated below; percentages are by volume.

' TABLEL w Base gasolines A B YD 'E 'F G H J Percent aromatics... 31.5 30 19.0 24.0 50 60 80 Percent olefinics 4.0 3 18.5 12.5 1O 2U 20 Percent saturates 64.5 67 62.5 63.5 50 90 100 EXAMPLElO A gasoline composition was prepared by adding to base gasoline A,3.l2 grams'of lead per gallon as tetraethyllead, about 1.35 grams of ethylene dibromide scavenger per gallon, about 1.49 grams of ethylene dichloride scavenger per gallon. and 500 parts per million (ppm) of reaction product of Example I.

EXAMPLE 11 EXAMPLE 12 A gasoline composition was prepared 'byj adding to base gasoline 5,3. l 5 grams of lead per gallon as tetraethyllead, about 1.43 grams of ethylenedichloride per gallon, about 1.51 grams of ethylene dibromide pergallon and 1.1 grams (400 ppm) of the reaction product of Example 5 per gallon.

EXAMPLE 13 A gasoline composition was prepared by adding to base gasoline B, 3.15 grams of lead per gallon as tetra ethyllead, about 1.43 grams of ethylene dichloride per EXAMPLE 14 A series of gasoline compositions is prepared by adding 50 ppm, ppm, 200 ppm, 700 ppm, 1,000 ppm of the product of Example? to each of base gasolines A through J.

i EXAMPLE 15 Another series of gasoline compositions is prepared by adding 1.0 grams of lead per gallon as a tetraethyllead, about 0.45. grams of ethylene dibromide and about 0.48 grams of ethylene dichloride'to each of the Example 14 compositions.

EXAMPLE l6 1 A gasoline composition was prepared by adding to base gasoline A, 3.12 grams of lead per gallon as tetracethyllead, about 1.35 grams of ethylene dibromide scavenger per gallon, about 1.49 grams of ethylene dichloride scavenger per gallon,*andl00 ppm'of the product of Example 2.

EXAMPLE 17 A gasoline composition is prepared by adding 50 ppm of didodecylbenzene to base gasoline C.

EXAMPLE 18 A gasoline composition is prepared by adding ppm of the product to Example 7 to the base gasoline EXAMPLE 2o A'gssuline composition is prepared by adding 450 ppm of the, product otExample 9 to base gasoline f EXAMP E 21 t A gasolinecomposition was prepared by adding-to base gasoline B,.3.-15 grams of lead per gallon as tetraethyllead, about 1.43 grams of lead per gallon of ethylene dibromide, about 1.51 grams of lead per gallon as ethylene dichloride, and 400 ppm of the blend of products from Example 6, Runs A through c.

v 3 EXAMPLE 22 A series of gasoline compositions is prepared by adding 450 ppm of each of (a) dioctacosylbenze'ne, (b) mixed C alkyldiphenyl having a 1200'mo1ecular weight, (c) 1,4,8-trieicosylfluorene, or (d) mixed'C alkylnaphthalenes having a 900 molecular weight in each of base gasolines A through J.

EXAMPLE 23 Another series of gasoline compositions is prepared by adding about 3 grams of lead per gallon as a tetraalkyllead antiknock and organohalide scavengers in the same proportions as in Examples 10 and 11, to the compositions of Example 22.

Examples 10 through 23 illustrate, but do not limit the gasoline compositions of the present invention. In other words, suitable gasoline compositions can be prepared using the alkyl aromatic hydrocarbons disclosed herein in any gasoline in the proportions taught above.

As pointed out previously, the alkyl aromatic hydrocarbon additives can conveniently be added to the base gasoline in the form of concentrates or fluids. These additive fluids would contain sufficient alkyl aromatic hydrocarbon additive and any other gasoline additive desired in the finished gasoline, such as antiknock agents (tetraethyllead, tetramethyllead, (methylcyclopentadienyl)manganese tricarbonyl), halohydrocarbon scavengers, phosphate deposit modifiers, dyes, antioxidants, and the like. The exact composition of such additive fluids is determined by the physical characteristics of the materials such as compatability, solubility, and the like, as well as the concentration desired in the finished gasoline.

The intake system deposit reducing effect of the additives of the present invention was determined by testing in an engine. The test procedure involved running a standard 6-cylinder automobile engine on the gasoline fule to be tested for a total of 60 hours on a severe intake valve deposit cycle. This cycle consisted of running the engine for 150 seconds at 2,000 revolutions per minute (rpm) followed by 40 seconds at 500 rpm for a total of 60 hours. At the end of this 60 hour test run, the manifold and head assemblies of the engine were removed for inspection. The intake valves were removed, weighted and photographed. The valves were then cleaned to remove all the accumulated deposits and reweighed. The total deposit weight was obtained by subtracting the weight of the valves after they had been cleaned from the weight of the valves with the accumulated deposits. In this way, a direct measure of the effect of an additive on intake valve deposit formation was obtained. In addition to this direct measurement, a cleanliness rating based on visual inspection of the intake system of the engine was also made. The rating was based on a visual observation of the carburetor throttle body, the intake riser, the hot spot, the branches and valve ports of the dissassembled engine, the Coordinating Research Council (CRC) rating scale found in the Varnish Rating Manual No. 9 and Sludge Rating Manual No. 10 was used as a base for assigning a numerical Cleanliness lndex.

Following is the data obtained in a series of such engine tests.

TABLE Intake Valve Deposit Reduction Amount of Alkyl Intake Re- Aromatlc Valve duction Clean- Test Gasoline Additive Deposits in liness No. Composition (PP (grams) Deposits Index 1 Base Gasoline A None 6.024 43.5 2 Example 10 500 0.615 90 45.5 3 Example 11 250 2.128 65 42.5 4 Example 12 400 1.21 43.0 5 Example 13 400 1.18 80 44.5

To Base Gasoline A was added substantially the same amount of the same tetraethyllead/organohalide antiknock fluid (Motor Mix) as in the compositions of Examples 10-13 Underhead Average of four runs 50 clean As the data above clearly show the alkyl aromatic hydrocarbon additives of the present invention significantly reduce the intake valve deposits in an internal combustion engine. These additives result in intake valve underhead deposit reductions ranging from 65/0 up to /0. The Cleanliness Index data also indicates that the entire intake system of the engine is benefitted when about 400 ppm or more of the present additives is used.

Comparable. intake valve. deposit reduction is obtained when the fuel compositions of the other examples (or any of the fuels containing the additives described herein) are used in an internal combustion engine. v

The present invention is embodied as described above, in a gasoline composition, a novel gasoline additive concentrate, a novel reaction product, and a method of reducing intake system deposits in an internal combustion engine. These embodiments have been fully and properly described above. The invention is limited only within the spirit and scope of the following claims.

I claim:

1. A productobtained from a process which comprises reacting a. an aromatic hydrocarbon selected from benzene,

Y C -C alkyl benzenes, diphenyl, C C alkyl diphenyls, naphthalene, C -C alkyl naphthalenes, anthracene, phenanthrene, fluorene, and indene with b. a mixture of even carbon number monoolefins ranging predominantly from about C to about C wherein at least 30/0 of the olefins have the vinyl type a-olefin configuration, at least 30/O of the olefins have the vinyldene type a-olefin configuration, and the remaining olefins have internal olefin configurations in the presence of a catalytic amount of selected from AlCl and AlBr and BE,

d. at reaction temperatures ranging from about 309C to the boiling point of the lower boiling of the tw reactants (a) and (b), said product having l an average molecular weight of from about 400 to about 1,200 and (2) intake valve deposit reducing effectiveness in gasoline.

2. A product obtained from a process of claim I wherein said aromatic hydrocarbon (a) is benzene, said olefin mixture (b) ranges predominantly from about C to about C ,said catalyst (c) is an aluminum halide, said reaction temperature (d) is about 70C. said product having an average molecular weight of from about 700'to about 800.

* I I i c. a catalyst In Column 2, line 59, "'ld ecyLQ-ttre ceoylan hrac ene" should Qifla? UNITED STATES-"QPATENII"OFFICE b ammonia; OF CORRECTION Patent No. 5 75 I ngg 'd Septembei'rll Inventorw) Warren L. Perfilstie ini I I I It in certified Sh at wtmrnQ sn p 5o311 's :ijifihv as v d mifi d atent I and that said Letters Patent are hexe'by corteqted asi shpwh below;

be ldecyl '2 tetradeoylantnr e oenem In Column 5, line 38, locbyllk'-hepblcsylbenZ6ne1""should be loctyl'-.4heptac osylbenzeneo- In Column 5 Tabl e 5), under ine-z beading:TfQ leifin Carbon No.

In Column 10, lines 5 2 55, Itebraoethyljleadi' shoul dibe In Column 11, line 33, "fule" be fuel In Column ll, li i "-I Signed and svee ll l cfthis} 1815,11 idaagy I (SEAL) Attesc:

EDWARD Ma FLETCHER, JR. RENEY'DQTEGTD'IEYER Attesting Officer Acting Commi'ssione'r of Patents 

2. A product obtained from a process of claim 1 wherein said aromatic hydrocarbon (a) is benzene, said olefin mixture (b) ranges predominantly from about C18 to about C30, said catalyst (C) is an aluminum halide, said reaction temperature (d) is about 70*C. said product having an average molecular weight of from about 700 to about
 800. 